Generic rotary piston engines are known for example from German patent specification DE 27432. A gear mechanism having several connecting rods acts here on two shafts running into one another, one of which is connected to the rotor and the other to the cylinder liner. The gear mechanism has a total of seven rotational joints, i.e. the mounting of the central shaft inside the hollow shaft, the mounting of the hollow shaft inside the frame and two connecting rods each with two rotational joints and a further connecting rod with a total of three rotational joints. The arrangement of the frame around the cylinder and the connecting rod restricts considerably the geometric dimensions of the gear mechanism and the angle range of a relative movement between rotor and cylinder liner.
Further generic rotary piston engines are for example known from the US patent specification U.S. Pat. No. 1,556,843, WO 00/79102 A1, DE 1926552 A1 and EP 0013947 A1.
DE 197 40 133 A1, DE 197 53 134 A1 and WO 2005/045198 A1 propose for a generic rotary piston engine oval-shaped gearwheels, which will scarcely lead to a feasible solution.
WO 2007/009731 A1 describes a very complicated and also scarcely feasible gear mechanism.
All these known rotary piston engines have in common the complicated structure of the gear mechanism, which couples the cylinder liner and the rotor to a relative movement periodically oscillating between a positive and negative rotational speed or to a periodically leading and lagging relative movement of the engine and the cylinder liner.